Professor Janarthanan Jayawickramarajah of Tulane University is supported by the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program of the Division of Chemistry to design and study the dynamics and programmable nature of nanomachines that can transduce input signals into specific outputs, such as motion and shape change. The introduction of different synthetic host-guest components, minimizes the dependence on costly long DNA chains, expands the types of inputs that can be utilized within the nanomachines and increases their versatility. Potential applications include the development of DNA machinery that have catalytic and chemical sensing functions. In addition to directly impacting nanotechnology, the project broadly impacts multiple scientific disciplines and provides the versatility needed for device development, such as logic gate devices, sensing/diagnostic agents, and autonomous systems. During the course of conducting this project, students are educated and trained in inter-disciplinary chemical research. Furthermore, research is integrated with teaching and community service via a chemistry-based service-learning course that involves Tulane undergraduate students conducting demonstrations at New Orleans K-12 public schools. In addition, the project includes a summer undergraduate research experience for diverse groups of students from mostly underrepresented minorities at neighboring Xavier University.
This project develops cucurbituril 7 (CB7) based host-guest driven toehold mediated strand displacement (TMSD) as a guiding principle to achieve dynamic supramolecular DNA machines. While conventional Watson-Crick based TMSD has been foundational in the development of elegant molecular devices (such as motors to carry and sort cargo, autonomous robots that control protein activity, and systems that conduct computing tasks), these DNA nanomachines have the drawback that they only harness genetic molecular recognition and thus the scope of inputs that the systems can incorporate (or respond to) is largely limited to nucleic acid sequences. This project utilizes synthetic supramolecular surrogates that can replace (or serve in a complementary fashion to) Watson-Crick base-pairing driven TMSD and thus generates nanomachines that are responsive to a broader variety of stimuli whilst also minimizing the length of the DNA domains that are used. Furthermore, by harnessing host-guest based TMSD, in addition to other salient supramolecular chemistry concepts (including multivalency and entropy-driven product formation), the project develops (a) higher-order supramolecular DNA circuits that are catalyzed by guest-linked DNA and (b) non-enzyme based sensors with the capacity for catalytically amplified fluorescence signaling.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
